/************************************************************************
 * Copyright (c) 1990, 1993
 *  The Regents of the University of California.  All rights reserved.
 * Copyright (c) <2014-2015>, <Huawei Technologies Co., Ltd>
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Chris Torek.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 ************************************************************************/

/************************************************************************
 * Notice of Export Control Law
 * ===============================================
 * Huawei LiteOS may be subject to applicable export control laws and regulations,
 * which might include those applicable to Huawei LiteOS of U.S. and the country
 * in which you are located.
 * Import, export and usage of Huawei LiteOS in any manner by you shall be in
 * compliance with such applicable export control laws and regulations.
 ************************************************************************/

#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)fgets.c 8.2 (Berkeley) 12/22/93";
#endif /* LIBC_SCCS and not lint */

#include "stdio.h"
#include "string.h"
#include "local.h"
#include "errno.h"
#include "asm/hal_platform_ints.h"
#include "hisoc/uart.h"

/*
 * Read at most n-1 characters from the given file.
 * Stop when a newline has been read, or the count runs out.
 * Return first argument, or NULL if no characters were read.
 */
char *
fgets(char * __restrict buf, int n, FILE * __restrict fp)
{
    size_t len;
    char *s;
#ifndef LOSCFG_FS_VFS
    int i = 0;
#endif
    unsigned char *p, *t;

    if (n <= 0)     /* sanity check */
    {
        errno = EINVAL;
        return ((char *)NULL);
    }

    if (fp == stdin)
    {
#ifndef LOSCFG_FS_VFS
        hal_interrupt_mask(NUM_HAL_INTERRUPT_UART);
        s = buf;
        for(i= 0; i < n - 1; i++)
        {
            s[i] = uart_getc();
            if(s[i] == 0x0d)
            {
                (void)uart_putc('\r');
                (void)uart_putc('\n');
                break;
            }
            (void)uart_putc(s[i]);
        }
        s[i] = '\0';
        hal_interrupt_unmask(NUM_HAL_INTERRUPT_UART);
        return buf;

#endif
    }

    FLOCKFILE(fp);
    _SET_ORIENTATION(fp, -1);
    s = buf;
    n--;            /* leave space for NUL */
    while (n != 0) {
        /*
         * If the buffer is empty, refill it.
         */
        if ((len = fp->_r) <= 0) {
            if (__srefill(fp)) {
                /* EOF/error: stop with partial or no line */
                if (s == buf) {
                    FUNLOCKFILE(fp);
                    return ((char *)NULL);
                }
                break;
            }
            len = fp->_r;
        }
        p = fp->_p;

        /*
         * Scan through at most n bytes of the current buffer,
         * looking for '\n'.  If found, copy up to and including
         * newline, and stop.  Otherwise, copy entire chunk
         * and loop.
         */
        if (len > (size_t)n)
            len = n;
        t = (unsigned char *)memchr((void *)p, '\n', len);
        if (t != NULL) {
            len = ++t - p;
            fp->_r -= len;
            fp->_p = t;
            (void)memcpy((void *)s, (void *)p, len);
            s[len] = 0;
            FUNLOCKFILE(fp);
            return (buf);
        }
        fp->_r -= len;
        fp->_p += len;
        (void)memcpy((void *)s, (void *)p, len);
        s += len;
        n -= len;
    }
    *s = 0;
    FUNLOCKFILE(fp);
    return (buf);
}
